1. Field of the Invention
The invention relates to an arrangement of a platform deck for oil rigs or the like, which rigs normally include vertical pilings, columns or other vertical supporting structures, together with a load-bearing structure which constitutes the main deck of the rig.
2. Description of the Prior Art
It has previously been usual that on the load-bearing structure or main deck of oil rigs so-called modules are mounted thereon which comprise a part of the necessary equipment for the platform. Such modules consist of a base (on which the various machines and other equipment are mounted), walls and a ceiling, such that each of the modules form enclosed box units. These modules can be very large in size, for example about 25 meters .times. 15 meters .times. 10 meters, and they can have weights of from 600 to 2000 tons. The modules are first built in work shops and are then towed on lighters to the installation site where they are lifted in place by means of large floating cranes.
The modules are dimensioned for support by the platform supporting structure, i.e., the large beams which structurally connect the supporting columns or the like. Thus the dimensions of the modules to a certain degree will be restricted by the supporting structure of the rig.
However, since such modules are often of great size and weight, they thus require extensive and costly precautions when brought in place on the main deck.
Moreover, the connection of pipes, etc., between the various modules is time consuming and complicated, especially when the pipes to be connected have different positions on the respective modules. Such connections for pipes have to be carried out in the narrow free passage between respective modules.
The object of the present invention is to provide a modification of the structural features for such oil rigs, to thereby obtain a simpler installation of the machines and equipment included therein, and at the same time achieve a very substantial saving in weight. This last mentioned feature can be of the greatest importance in the case of rigs where the equipment is entirely or partly installed onshore before towing to an offshore location. The weight of the total top structure will then be of critical significance, e.g. with respect to its stability.